1. Field of the Invention
Embodiments of the present invention generally relate to a downhole expansion assembly. More particularly, embodiments of the present invention relate to seals for the downhole expansion assembly.
2. Description of the Related Art
In the oilfield industry, downhole tools are employed in the wellbore at different stages of operation of the well. For example, an expandable liner hanger may be employed during the formation stage of the well. After a first string of casing is set in the wellbore, the well is drilled a designated depth and a liner assembly is run into the well to a depth whereby the upper portion of the liner assembly is overlapping a lower portion of the first string of casing. The liner assembly is fixed in the wellbore by expanding a liner hanger into the surrounding casing and then cementing the liner assembly in the well. The liner hanger includes seal members disposed on an outer surface of the liner hanger. The seal members are configured to create a seal with the surrounding casing upon expansion of the liner hanger.
In another example, a packer may be employed during the production stage of the well. The packer typically includes a packer assembly with seal members. The packer may seal an annulus formed between production tubing disposed within casing of the wellbore. Alternatively, some packers seal an annulus between the outside of a tubular and an unlined borehole. Routine uses of packers include the protection of casing from pressure, both well and stimulation pressures, and protection of the wellbore casing from corrosive fluids. Packers may also be used to hold kill fluids or treating fluids in the casing annulus.
Both the liner hanger and the packer include seal members that are configured to create a seal with the surrounding casing or an unlined borehole. Each seal member is typically disposed in a groove (or gland) formed in an expandable tubular assembly of the liner hanger or packer. However, the seal member may extrude out of the groove during expansion of the expandable tubular assembly due to the characteristics of the seal member. Further, the seal member may extrude out of the groove after expansion of the expandable tubular assembly due to pressure differentials applied to the seal member. Therefore, there is a need for extrusion-resistant seals for use with an expandable tubular assembly.